NAVNi-Stuff

maandag 29 juni 2015

I recently bought a very basic telescope (Celestron Travel Scope 70), not exactly a high end telescope, but I'm still able to get some nice views on planets like Saturn, Jupiter and its moons, Venus and off course the moon.

Being enthusiastic about what I could see with this telescope I have tried taking photographs by manually putting my cell phone camera against the eye piece and minimize my trembling while pushing the button to take picture.

Not surprising that image quality is far from good. For pics of the moon, it sometimes works out ok.

cropped image of the moon taken with my cell phone camera held against my telescopes eye piece

But while the features of Saturn are just distinguishable with the naked eye, it's almost impossible to take a nice picture with the methods described above.

image of Saturn taken with my cell phone camera held against my telescopes eye piece

Also Jupiter and its moons are hard to catch.

image of Jupiter and moons taken with my cell phone camera held against my telescopes eye piece

Taking it up a notch

Due to this less than ideal situation I decided to take things up a notch and use a raspberry pi camera. I printed an adapter for the Pi Camera to slide over my eye piece using my 3D printer. After some filing and a paint job I have the adapter ready and I secure the Pi Camera into the adapter with some duct tape.

The idea is to eliminate tremor from holding the cell phone against the eye piece and being able to control the camera remotely. Eventually I would like to be able to take a clear picture of both Saturn and Jupiter (and its moons).

Powering the raspberry pi

Mount Raspberry pi on telescope.

Currently the Raspberry Pi is basically mounted on the telescope with some zip ties.

To be more comfortable I might need to add a longer ribbon cable between the camera and the Raspberry Pi.

Aiming the telescope

While the Raspberry Pi camera is on the telescope it would be hard to aim it very precisely. Therefore, I setup streaming so I could check the aiming of the telescope with a laptop or cell phone (as long as I am within reach of my WiFi network) by following this guide.

Taking pictures with Raspberry Pi

Once I somewhat correctly aimed my telescope I could use the regular Raspberry Pi Camera commands to take pictures of the celestial bodies.

Impressions so far

The pictures I took were not so good as the ones taken with the cell phone, but that is probably due to the low resolution used to take the pictures with the Raspberry Pi Camer.

The way the current adapter is made, it is very fidgety to get it well aligned with the projection from the eye piece. I have the impression I will have to redesign the eye piece adapter even further to make fitting the adapter on the eye piece easier and to put the raspberry pi camera lens even closer to the eye piece.

Luckily both the Raspberry Pi and the laptop used for aiming were both within reach of my WiFi.

The USB battery could provide sufficient power for the 1 hour I have been testing my setup.

Some test results from 29/06/2015:

Moon in 640x480 resolution

Saturn in 640x480 resolution

Test results 30/06/2015:

moon in 2592 x 1944 resolution

saturn in 2592 x 1944 resolution

arcturus in 2592 x 1944 resolution

Although shot in higher resolution, the improvement is not that great. The Saturn pic at least shows some interesting shadows. Not sure whether this is due to my setup, or taking pictures in 'automatic' mode (without defining ISO, brightness, contrast, ...), atmosphere (very warm when pictures were taken) or the limits of my telescope (although naked eye observatory is quit good).

Future ideas / improvements

I need to improve the resolution (max resolution is 2592 x 1944, would much better than 640 x 480)

Definitely need to start experimenting with my camera settings to get better images

automated following / finding, although my Raspberry Pi setup is streaming so I can aim the telescope somewhat while looking at my laptop screen, it would be cool to punch in a celestial body to find and/or follow

touchscreen control on Raspberry Pi

Have the raspberry pi act as its own APD (or the laptop that is controlling the Raspberry Pi camera) for when I'm not within my home's WiFi range.

donderdag 9 april 2015

When googling around for this, a lot of solutions came down to replacing a defective USB cable with a new one. However, in my case I was sure that the issue was not caused by a bad USB cable as printing directly from laptop using the same USB cable went fine.

The solution to this problem simply came down to adding the following line to the /boot/config.txt file of my Raspbian install:

zondag 30 november 2014

This summer, on the beach, I found a nice piece of drift wood that I brought home with me.

I let it dry for a few months and yesterday I transformed it in a tea light holder in just a few minutes.

I started out be positioning some tea lights on the wood to see what would look nice. I marked the location of the tea lights on the log and took it outside.

Once outside, I mounted a hole saw on my hand drill and carefully started to drill out the marked locations. I made sure I was not drilling whole the way through. After this, I cleaned up the holes with a small chissel.

donderdag 13 maart 2014

I'm in progress of getting an old backup server back in service for taking backups of my fathers computer. One of the upgrades, next to external storage, was to replace current 4GB memory with 4 x 4 GB memory DIMMS.

To my horror, after installing the DIMMS, the server no longer boots!!!!!!

So I tried all kinds of DIMM configurations, reset the CMOS, removed the motherboard battery, unplugged all devices, BIOS upgrade, ... all to no avail

Major panic, sweat, sickness, anger,....

Then I noticed after the n'th test that when inserting the new DIMM's a LED flashed on the motherboard. Than it hit me, the DIMMS are situated next to the motherboard's power connector and when pushing on the power connector, it nudged itself slightly deeper into the socket.

Reboot

TADAAAAA a working system!!!!

Finally I can continue setting up this system. Lesson learnt: always check all connectors.

maandag 6 januari 2014

This is still a work in progress and if you got tips or comments, let me know. I will update this blog post as I am further in my setup.

One of the downsides of using a Raspberry pi as a NAS solution is a somewhat low speed in transferring data. This is partially caused by the fact that in my previous NAS setup I'm using external USB HD's.

I came across some the cubieboard and what jumped out to me in the specs is that it has a SATA connector on the board, so I immediately wanted to give it a try.

Through ebay I bought a 'Cubieboard A10 ARM Development board luxurious package'. This kit contained a cubieboard one (developer edition), an enclosure, a 3.5" HDD addon board, a TTL to Serial cable, a breadboard with VGA connector, a uSD breakout PCB and a heatsink. I was especially interested in the 3.5" HDD addon board as I am planning to combine the cubieboard with a Seagate 2TB SSHD.

To make this whole setup work I had to buy a microSD card to host the OS and an external power adapter (Ansmann APS 1500 traveller) to supply adequate power to the cubieboard and the HD.

Hardware setup

Seagate 2TB SSHD 3.5"

Cubieboard mounted in its enclosure

3.5" HD adapter

external power supply (providing 12V, 1500mA)

Writing a linux image to the microSD card

The microSD card came with an adapter card that could easily be plugged into my computer.

I downloaded/unpacked the Cubian image and write it to the microSD card.

I first went for the Lubuntu image, but that starts a XWindows by default, which is too much overhead for what will essentially be a headless node. Turning off the XWindows environment would be too much work so I decided to go for the Cubian image, which is a debian derivative. As the raspberry pi NAS also uses a debain flavoured distro, I think this might be the safest path to take.

sudo smbpasswd -a <username>adds the day-to-day user to the samba usersI was able to mount the cubie NAS share automatically on my notebook by adding the following in /etc/fstab and running sudo mount -a afterwards:

However this did not initially work I had to install some extra software on the cubieboad to make it work:

sudo apt-get install ciffs-utils

After installing the ciffs-utils and running sudo mount -a, I had access to the raspberry pi's data.

Metrics

First test I did was copy an 734MB iso file from my notebook to both the raspberry pi nas and the cubienas.$ time cp ~/Downloads/ubuntu-12.04.4-desktop-amd64.iso ./cubiedisk/real6m31.366suser0m0.004ssys0m2.992s$ time cp ~/Downloads/ubuntu-12.04.4-desktop-amd64.iso ./Disk1/real6m29.708suser0m0.000ssys0m2.888s

What?! It took approx as much time to copy it to the raspberry pi NAS setup as it did to copy it to the cubieboard. The only explanation I have for this is that I'm connecting to these NAS setups via powerlan. And that might just be too slow to make a difference when transferring data.

When I'm having my laptop connected to the switch close to the NAS setups these are the results:

Setup a wireless router connected to the switch next to the NAS setups.

See if mounting the disks using NFS might be better performing than mounting them as Samba mounts

Unresponsive CubieNAS

Each attempt at synching the cubieboard overnight with my other storage ended up with an unresponsive CubiebardNAS setup. I could enter the necessary credentials for ssh, but I never get to a prompt. After a few times even booting no longer succeeds. The last message appearing on my screen is "Mali: Mali device driver loaded" and than nothing. To be sure there was nothing else happening in the back ground I connected a UDB-serial cable to the cubieboards TTL connector and executed:

cu -s 115200 -l /dev/ttyUSB0

just after booting. This showed me similar data as on the connected screen but it also showed

So several cold reboots caused some errors on de file system. So I guess I will need to be patient until the fsck is finished.

I continued to check the hard drive using the SMART disk monitoring tools, following this article. These tests did not turn up any hard drive problems, so basically cold rebooting the cubieboad NAS caused the file system errors. I haven't looked at setting up SMART as a daemon, but I'll investigate it in the future to have this setup on all my machines.

The next test I performed was to start syncing again between my raspberry pi NAS and the cubieboad NAS and redirecting all output to log files on the SATA drive. If something was going to happen during sync I hoped the log files might contain some clues after I reboot the system. But actually, after a lot of big syncs the cubieboard was still up and running. So I guess the system freezes were caused by any output of the syncing not being redirected to output files.

My DIY home projects

This blog is intended to document the projects that I'm working on in my spare time. This covers home made furniture, IT equipment, japanese language learning and whatever else I find worth blogging about :-)